1. Field of the Invention
The present invention related to an apparatus and method for producing a composite elasticized web, with elastic sections spaced from each other by a constant pitch in the longitudinal direction of the web.
The present invention has been developed in particular for the production of elastic webs intended to be applied in the waist region of disposable absorbent sanitary articles. However, the scope of the invention is not limited to this possible field of application.
2. Description of Prior Art
Absorbent sanitary products for adults are often obtained by two continuous composite webs spaced apart in a transverse direction and advancing in the longitudinal direction, between which extend absorbent cores arranged transversely to the longitudinal direction. The composite webs form front and rear waist regions of the absorbent sanitary products. The waist regions are often provided with elastic bands in order to confer to the absorbent product improved adherence to the wearer.
An established technique for the production of elastic webs for absorbent sanitary products involves applying a continuous elastic film in a tensioned state between two webs of non-woven. In the case of absorbent products for adults it would be appreciated to have composite elastic tapes in which the elastic film is interrupted in correspondence of the absorbent core.
US2010/0051170 describes a process for producing an elasticized composite web with intermittent elastic sections. The process described in this document includes: forming sections of stretched elastic sheets starting from a continuous elastic sheet, feeding a continuous web in the longitudinal direction, applying the elastic sections intermittently on the continuous web with the stretching direction of the elastic sections aligned to the longitudinal direction of the sheet, fixing by adhesive the opposite ends of the elastic sections to the continuous web, and fixing by ultrasonic welding the elastic sections and the continuous web in intermediate areas between the opposite end portions by means of a pattern of spot welding.